Las mackenzie



(No Model.)

J. K. D. MACKENZIE.

ELEGTRIGAL SIGNALING APPARATUS. No. 305,611. Patented Sept. 23, 1884.

Nitrite {States J KENNETH 'D. MACKENZIE, OF

, ENGLAND.

ELECTRICAL SIGNALING APPARATUS.

" SFECIFICATIUN forming part of Letters Patent No. 305,611, datedSeptember 23, 1-884.

Application filed June 1 188-1. (No model.) Patented in England May 27,1884, No. 8,305. 7

To a ll whom,v it Jim/y 001 m Be it known that 1, JAMES KENNETH Douc-LAS MACKENZIE, electrical engineer, a subject of the Queen of GreatBritain and Ireland,and

residing at 25 Queen Annes Gate, Westminster, in the county oflVIiddlesex,England,have invented a certain Apparatus for Indicating theProper lVorking of Electrical Annunciators, (for which I have appliedfor apatent in Io Great Britain, No. 8,305, dated May 27, 1884,)

of which the following is a specification.

The object of my invention is to provide a means by which the properworking of. an electric bell or other annunciator is indicated I 5 atthe distant push or contact, or at other desired place where the soundof the bell or annunciator cannot itself be heard, which means shall beautomatic, simple, and inexpensive. The person operating the push orcontact will thus be certain that the bell is ringing, and that thecircuit is in proper working order. The means I employ according to myinvention for obtaining this result consist in employing the wellknownproperty of iron,which is that of emittinga sound when magnetized ordemagnetized. For this purpose I arrange an electromagnet in theannunciatorcircuit, the core of which is magnetized and demagnetizedwhen the contact is made and the said circuit is acting properly, and incombination with this I use" a piece or disk of iron,which may form partof the core magnetically, and which emits sounds as the core ismagnetized and demagnetized.

In carrying my invention into effect I may 3 5 take a box, preferablyround, formed of iron of any convenient size, and fasten to the insideof the bottom a small core of soft iron almost the height of the box.Around this core of soft iron I place a bobbin or helix of wire, whichforms part of the annunciator-circuit. Over the other end of thesoft-iron core, but not touching it, and fastened to the edge of thebox, Iplace a disk of thin iron,forming alid or cover, and also,preferably, the opposite pole of 5 the soft-iron core. The box is thusclosed completely. The two ends of the wire forming the before-mentionedbobbin or helix are led out through and insulated from the side of thebox, and are connected in the circuit of theannunciator. When contact ismade in the circuit, the current flows round the bobbin theelectro-ma-gnets of the annunciator through the break-and-makearrangement and back to the source of electricity. While the current isflowing it magnetizes the core of soft iron,and each time the circuit isinterrupted or broken by the break-and-make arrangement of theannunciator the magnetism of the soft-iron core is lost and a sound isgiven out. When the break-and-make arrangement again completes thecircuit, the magnetism of the core is renewed and a sound is again givenout, and this sound, caused by the magnetization and demagnetization ofthe iron, continues to be given out so long as the bell is being rung. Iprefer to polarize the lid, as hereinbefore mentioned, as the effect isthereby increased. If the annunciator failed to act, or the circuit benot completed,the core would not become magnetized, and therefore nosound would be given out by my indicator. I combine my indicator withany contact-maker or ordinary bell push or pull.

In order that the said invention may be fully larly to describe thesame, and for that purpose sh all refer to the several figures on theannexed sheet of drawings, the same letters of reference indicatecorresponding parts in all the figures.

Figure 1 represents in section, and Fig. 2 in plan, an apparatusarranged according to my invention, and is shown in combination with anordinary contact-maker.

A is the iron boxpB, the bottom. to which is attached the soft-iron core0, around which is the-bobbin or helix E. I

D is the iron lid or cover of the box A, and attached thereto oppositethe end of the core G.

F F arethe two contact-springs, and P is the push. Fig. 3 is atheoretical diagram of connections,showing the bell and battery. In Fig.8, when F F are joined, the current flows from the battery round thebobbin or helix E to the bell round the magnets through themakeand-break arrangement and back to the battery, thereby polarizingthe core 0 and the The make-and-break arrangement of the bell now comesinto action and the circuit is inand the lid D, and causing it again toemit a or helix of my indicator along the line around terrupted, therebydemagnetizing the core 0,

WESTMINSTER, COUNTY OF MIDDLESEX,

understood, I shall now proceed more particulid D, and causing the saidlid to emit asound.

sound. I find that this sound, caused by de- I magnetization, is louderthan that caused by magnetization, and therefore my apparatus is capableof being used as a means of transmitting messages orally. Thisinterrupted and intermittent sound is kept up so long as thecontact'between F and F is maintained and the battery-current lasts.Other electrical power than that produced by batteries may be used, andthe instrument may be combined with any apparatus in which electricbells are usedsuch as telephone call-bells.

I have shown in the drawings the lid of the box as connected with thecore, so as to be polarized thereby; but I do not necessarily limitmyself to this.

11 claim- In an electrical 'annunciator-circuit, the I combination, withthe make-and-break apparatus at the distant station, of anelectro-magnet at the sending-station, adapted to be magnetized anddemagnetized by the action of the make-and-break apparatus, and an irondisk or box and connections, arranged and adapted to coact with saideleetro-magnet, substantially as hereinbefore set forth.

- In testimony whereof I have signed my name to this specification inpresence of two subscribing witnesses.

J KENNETH D. MACKENZIE. Witnesses:

CHAS.- MILLs, OHAs. J AS. J ONES, Both 0f,47.Linc0l'/z7s Inn Fields,London.

